When preparing text in a Western language, it is widely known to print the text by formatting it in a desired style, such as conforming the text to the size of the sheet for printing, filling, and performing justification. The functions, operations and actual implementations of such a formatting program are well known to those skilled in the art, and a number of reference articles are available. Thus, further explanation for the formatter itself is omitted here. As one of the reference articles, consult Chapter 7 "Text Formatting" pp. 335-386 of Software Tools" (Authors: Brian W. Kernighan, P. J. Plauger, Translator: Izumi Kimura, published by Kyouritsu Shuppan Co.).
The formatting programs of the prior art were used only for formatting text in Western languages. In recent years, however, Japanese text processing has been regarded as important, and thus it has been desired for a formatting program to work well not only on Western text but also on text containing Kanji characters in the similar manner. Furthermore, it is desirable for the formatting program to output formatted text in non-Western language other than Japanese as well, including Chinese and Korean. In implementing a multi-language supporting text formatting apparatus, new problems have arisen.
Among them is a problem relating to format restriction processing. Format restriction processing, as is well known, operates so that particular characters are not placed at the beginning or end of a line of text. For example, when the punctuation mark "." comes at the beginning of a line, it will be prevented from appearing at the beginning of that line by placing characters from the end of the previous line ahead of it.
In the formatting programs of the prior art for Japanese text processing, the sets of the characters forbidden to be placed at the beginning of a line or at the end of a line were fixed, and their character codes were buried in its program codes. Thus, it was impossible for the user to modify these character sets later. When it was required to use such programs not only for Japanese but also for Chinese, Korean and so on, however, a new problem would arise regarding format restriction processing. That is, the character sets to which the format restriction processing is applied are different among these languages. Even if there were a common character thereto, its character code representation might be different. Furthermore, even in one language, the characters that are to be format-restricted may be different among individual persons. The prior text formatting apparatus could not deal with such a situation.
Accordingly, one object of the present is to solve the problem of the prior art described above and to handle the differences in format restriction processing among languages as well as among individual persons.